I don't have a hardcore breakdown yet, but insofar I haven't seen anything that leads me to think ISXJ for you.
TBH, even with no type listed, you have given me an INXJ impression from day one (though that was only a couple of weeks back for me). Something about the way that you approach type and cognitive functions, and the way that you give advice on life, as well as your general speaking pattern, reads introverted intuitive to me. The only thing I wasn't sure of is INFJ or INTJ, because I see both Fi and Ti tendencies from you, but I have no reason to doubt INFJ at this point.
This could be due to not having enough experience with ISXJs on this forum. Or it could be my finely tuned type radar finally waking up from its deep slumber
But I'll continue to take this into consideration.
Yeah I get general reads of people vibing like Ni doms, and part of the reason is "they vibe like me". So it definitely would surprise me if I really was Si dominant.
I'm pretty sure I have primarily seen both Ni and Ti in you, so I don't really think ISFJ is that plausible for you? You're very theoretical in nature in a way that I really don't see from sensing types in general. Especially sensing dominants. I'd be curious where you think you have Si, just because I didn't get that impression from you, though not knowing your personally I could perhaps be missing something.
Yeah I've had someone else mention Ni and Ti as well. Maybe multiple people. People irl who I ask (who don't necessarily know more than the basics of type) tend to guess I am INT. I've always been very theoretical, for as long as that term made sense to apply to people. I remember in first grade we played a dice game where you had to roll two dice and subtract one number from the other. One kid asked "which number do we subtract?" and the teacher answered "it has to be the smallest number or it wouldn't work", and I was like "what about negative numbers?" haha. I've also been into philosophy since I was at least 13. Free will, right and wrong, reality - those kinds of questions amongst others.
So yeah, the theoretical aspect makes sense for INFJ with Ni+Ti (I would say Ni, Ne and Ti are the most theoretical functions), but ISFJ would surely be quite different from that, although I know that ISFJs can get into philosophy and such as well.
Probably the main reason I was having doubts (the doubts come and go) is because when I look at my social circle irl... it's mostly SFs. When I look at the music I listen to... it's mostly SFs. Especially male ISFJ and female ESFP, that's a big pair of types in my life. Even in my (extended) family - male ISFJs and female SFPs.
So it was like... I'm constantly surrounded by that pairing of types... maybe I AM an ISFJ?
However, as far as friends etc. go, I do find that I relate quite well to INTJs. Like we bond on a level that wouldn't make sense if I were ISFJ.
Regarding where I think I have Si, it's just for things like paying attention to what I'm doing, or remembering things. Basic stuff. Everyone gets that stuff because everyone has Si. But I generally don't think "oh, that's my Ni activating", I guess because Ni is a more surreal function where it's harder to pinpoint when it's operating. Si is more straightforward.
Sometimes when I'm speaking I do Si speech, but my secondary types model predicts that I sometimes would, so that wouldn't be a problem. Right now when I speak I'm doing Ni speech. Ni speech has a forward, continuous motion, Si speech has a forward, emphatic/pointed motion.